<?php !defined( 'SUNCMS' ) && exit( 'No direct script access allowed'  );

/**
 * 
 * Sun CMS
 * 
 * @author			Burning
 * @copyright		Copyright (c) 2009, IsunCms.Com.
 * @license			http://www.isuncms.com/license.htm
 * @link				http://www.isuncms.com/
 * @since				Version 1.0 Beta
 * 
 */

class json{

	var $at   = 0;
	var $ch   = '';
	var $text = '';

	function encode($arg)
	{

		$returnValue = '';
		$c           = '';
		$i           = '';
		$l           = '';
		$s           = '';
		$v           = '';
		$numeric     = true;

		switch (gettype($arg))
		{
			case 'array':
				foreach ($arg AS $i => $v)
				{
					if (!is_numeric($i))
					{
						$numeric = false;
						break;
					}
				}

				if ($numeric)
				{
					foreach ($arg AS $i => $v)
					{
						if (strlen($s) > 0)
						{
							$s .= ',';
						}
						$s .= $this->encode($arg[$i]);
					}

					$returnValue = '[' . $s . ']';
				}
				else
				{
					foreach ($arg AS $i => $v)
					{
						if (strlen($s) > 0)
						{
							$s .= ',';
						}
						$s .= $this->encode($i) . ':' . $this->encode($arg[$i]);
					}

					$returnValue = '{' . $s . '}';
				}
				break;

			case 'object':
				foreach (get_object_vars($arg) AS $i => $v)
				{
					$v = $this->encode($v);

					if (strlen($s) > 0)
					{
						$s .= ',';
					}
					$s .= $this->encode($i) . ':' . $v;
				}

				$returnValue = '{' . $s . '}';
				break;

			case 'integer':
			case 'double':
				$returnValue = is_numeric($arg) ? (string) $arg : 'null';
				break;

			case 'string':
				$returnValue = '"' . strtr($arg, array(
					"\r"   => '\\r',    "\n"   => '\\n',    "\t"   => '\\t',     "\b"   => '\\b',
					"\f"   => '\\f',    '\\'   => '\\\\',   '"'    => '\"',
					"\x00" => '\u0000', "\x01" => '\u0001', "\x02" => '\u0002', "\x03" => '\u0003',
					"\x04" => '\u0004', "\x05" => '\u0005', "\x06" => '\u0006', "\x07" => '\u0007',
					"\x08" => '\b',     "\x0b" => '\u000b', "\x0c" => '\f',     "\x0e" => '\u000e',
					"\x0f" => '\u000f', "\x10" => '\u0010', "\x11" => '\u0011', "\x12" => '\u0012',
					"\x13" => '\u0013', "\x14" => '\u0014', "\x15" => '\u0015', "\x16" => '\u0016',
					"\x17" => '\u0017', "\x18" => '\u0018', "\x19" => '\u0019', "\x1a" => '\u001a',
					"\x1b" => '\u001b', "\x1c" => '\u001c', "\x1d" => '\u001d', "\x1e" => '\u001e',
					"\x1f" => '\u001f'
				)) . '"';
				break;

			case 'boolean':
				$returnValue = (string) $arg;
				break;

			default:
				$returnValue = 'null';
		}

		return $returnValue;
	}

	function decode($text,$type=0) // 默认type=0返回obj,type=1返回array
	{
		if (empty($text))
		{
			return '';
		}
		elseif (!is_string($text))
		{
			return false;
		}


		$this->at   = 0;
		$this->ch   = '';
		$this->text = strtr(stripslashes($text), array(
				"\r"   => '', "\n"   => '', "\t"   => '', "\b"   => '',
				"\x00" => '', "\x01" => '', "\x02" => '', "\x03" => '',
				"\x04" => '', "\x05" => '', "\x06" => '', "\x07" => '',
				"\x08" => '', "\x0b" => '', "\x0c" => '', "\x0e" => '',
				"\x0f" => '', "\x10" => '', "\x11" => '', "\x12" => '',
				"\x13" => '', "\x14" => '', "\x15" => '', "\x16" => '',
				"\x17" => '', "\x18" => '', "\x19" => '', "\x1a" => '',
				"\x1b" => '', "\x1c" => '', "\x1d" => '', "\x1e" => '',
				"\x1f" => ''
		));

		$this->next();
		$return = $this->val();

		$result = empty($type) ? $return : get_object_vars($return);

		return addslashes($result);
	}

	/**
	 * triggers a PHP_ERROR
	 *
	 * @access   private
	 * @param    string    $m    error message
	 *
	 * @return   void
	 */
	function error($m)
	{
		trigger_error($m . ' at offset ' . $this->at . ': ' . $this->text, E_USER_ERROR);
	}

	/**
	 * returns the next character of a JSON string
	 *
	 * @access  private
	 *
	 * @return  string
	 */
	function next()
	{
		$this->ch = !isset($this->text{$this->at}) ? '' : $this->text{$this->at};
		$this->at++;

		return $this->ch;
	}

	/**
	 * handles strings
	 *
	 * @access  private
	 *
	 * @return  void
	 */
	function str()
	{
		$i = '';
		$s = '';
		$t = '';
		$u = '';

		if ($this->ch == '"')
		{
			while ($this->next() !== null)
			{
				if ($this->ch == '"')
				{
					$this->next();

					return $s;
				}
				elseif ($this->ch == '\\')
				{
					switch ($this->next())
					{
						case 'b':
							$s .= '\b';
							break;

						case 'f':
							$s .= '\f';
							break;

						case 'n':
							$s .= '\n';
							break;

						case 'r':
							$s .= '\r';
							break;

						case 't':
							$s .= '\t';
							break;

						case 'u':
							$u = 0;

							for ($i = 0; $i < 4; $i++)
							{
								$t = (integer) sprintf('%01c', hexdec($this->next()));

								if (!is_numeric($t))
								{
									break 2;
								}
								$u = $u * 16 + $t;
							}

							$s .= chr($u);
							break;
						case '\'':
							$s .= '\'';
							break;
						default:
							$s .= $this->ch;
					}
				}
				else
				{
					$s .= $this->ch;
				}
			}
		}

		$this->error('Bad string');
	}

	/**
	 * handless arrays
	 *
	 * @access  private
	 *
	 * @return  void
	 */
	function arr()
	{
		$a = array();

		if ($this->ch == '[')
		{
			$this->next();

			if ($this->ch == ']')
			{
				$this->next();

				return $a;
			}

			while (isset($this->ch))
			{
				array_push($a, $this->val());

				if ($this->ch == ']')
				{
					$this->next();

					return $a;

				}
				elseif ($this->ch != ',')
				{
					break;
				}

				$this->next();

			}

			$this->error('Bad array');
		}
	}

	/**
	 * handles objects
	 *
	 * @access  public
	 *
	 * @return  void
	 */
	function obj()
	{
		$k = '';
		$o = new StdClass();

		if ($this->ch == '{')
		{
			$this->next();

			if ($this->ch == '}')
			{
				$this->next();

				return $o;
			}

			while ($this->ch)
			{
				$k = $this->str();

				if ($this->ch != ':')
				{
					break;
				}

				$this->next();
				$o->$k = $this->val();

				if ($this->ch == '}')
				{
					$this->next();

					return $o;
				}
				elseif ($this->ch != ',')
				{
					break;
				}

				$this->next();
			}
		}

		$this->error('Bad object');
	}

	/**
	 * handles objects
	 *
	 * @access  public
	 *
	 * @return  void
	 */
	function assoc()
	{
		$k = '';
		$a = array();

		if ($this->ch == '<')
		{
			$this->next();

			if ($this->ch == '>')
			{
				$this->next();

				return $a;
			}

			while ($this->ch)
			{
				$k = $this->str();

				if ($this->ch != ':')
				{
					break;
				}

				$this->next();
				$a[$k] = $this->val();

				if ($this->ch == '>')
				{
					$this->next();

					return $a;
				}
				elseif ($this->ch != ',')
				{
					break;
				}

				$this->next();
			}
		}

		$this->error('Bad associative array');
	}

	/**
	 * handles numbers
	 *
	 * @access  private
	 *
	 * @return  void
	 */
	function num()
	{
		$n = '';
		$v = '';

		if ($this->ch == '-')
		{
			$n = '-';
			$this->next();
		}

		while ($this->ch >= '0' && $this->ch <= '9')
		{
			$n .= $this->ch;
			$this->next();
		}

		if ($this->ch == '.')
		{
			$n .= '.';

			while ($this->next() && $this->ch >= '0' && $this->ch <= '9')
			{
				$n .= $this->ch;
			}
		}

		if ($this->ch == 'e' || $this->ch == 'E')
		{
			$n .= 'e';
			$this->next();

			if ($this->ch == '-' || $this->ch == '+')
			{
				$n .= $this->ch;
				$this->next();
			}

			while ($this->ch >= '0' && $this->ch <= '9')
			{
				$n .= $this->ch;
				$this->next();
			}
		}

		$v += $n;

		if (!is_numeric($v))
		{
			$this->error('Bad number');
		}
		else
		{
			return $v;
		}
	}

	/**
	 * handles words
	 *
	 * @access  private
	 *
	 * @return  mixed
	 */
	function word()
	{
		switch ($this->ch)
		{
			case 't':

				if ($this->next() == 'r' && $this->next() == 'u' && $this->next() == 'e')
				{
					$this->next();

					return true;
				}
				break;

			case 'f':
				if ($this->next() == 'a' && $this->next() == 'l' && $this->next() == 's' && $this->next() == 'e')
				{
					$this->next();

					return false;
				}
				break;

			case 'n':
				if ($this->next() == 'u' && $this->next() == 'l' && $this->next() == 'l')
				{
					$this->next();

					return null;
				}
				break;
		}

		$this->error('Syntax error');
	}

	/**
	 * generic value handler
	 *
	 * @access  private
	 *
	 * @return  mixed
	 */
	function val()
	{
		switch ($this->ch)
		{
			case '{':
				return $this->obj();

			case '[':
				return $this->arr();

			case '<':
				return $this->assoc();

			case '"':
				return $this->str();

			case '-':
				return $this->num();

			default:
				return ($this->ch >= '0' && $this->ch <= '9') ? $this->num() : $this->word();
		}
	}
}